The Church of Saint Susanna at the Baths of Diocletian is located on the Quirinal Hill in Rome. There has been a titular church associated to its site as far back as AD 280. The current church was rebuilt from 1585 to 1603 for a monastery of Cistercian nuns founded on the site in 1587 which still exists there.
About 280, an early Christian house of worship was established on this site, which, like many of the earliest Christian meeting places, was in a house. According to the 6th-century document, the domus belonged to two brothers named Caius and Gabinus, prominent Christians. Santa Susanna is one of the oldest titles in the city of Rome. The early Christian church, built on the remains of three Roman villas still visible beneath the monastery, was situated immediately outside the wall of the Baths built by Diocletian and the Servian Wall, the first walls built to defend the city. The first three-aisled basilica was almost certainly built under the pontificate of Pope Leo III (795-816).
Pope Leo III rebuilt the church from the ground in 796, adding the great apse and conserving the relics of the saints in the crypt. A vast mosaic of Christ flanked by Leo and the Emperor Charlemagne and Saints Susanna and Felicity on the other was so badly damaged in the 12th century by an earthquake, that the interior was plastered over in the complete renovation that spanned the years 1585-1602 and frescoed by Cesare Nebbia.
Pope Sixtus IV (1475-1477) proceeded to rebuild the Church, probably a single nave with two side chapels. In 1588 it became the last great rebuilding effort of Cardinal Girolamo Rusticucci, Cardinal protector of the Cistercian Order, with construction running from 1595 to 1603.
The altarpiece of the high altar, depicting the beheading of St. Susanna, is by Tommaso Laureti of Palermo (1530-1602). Through the glass floor of the sacristy can be seen part of the early Christian Church and the remains of the Roman house, which is said to be the home of the father of the saint.
The church consists of a single nave, with a circular apse forming two side-chapels. The frescoes of the central nave by Baldassare Croce represent six scenes from the life of Susanna found in the Book of Daniel. The frescoes on the curved side of the apse shows Saint Susanna being threatened by Maximian, but defended by the angel of God and to the right, Susanna refusing to worship the idol Jupiter. Nebbia's frescoes of the dome of the apse depict Saint Susanna flanked on either side by angels with musical instruments. Behind the high altar, the painting depicting the beheading of Saint Susanna is by Tommaso Laureti.
Domenico Fontana constructed the second side-chapel to the left dedicated to Saint Lawrence, commissioned by Camilla Peretti, sister of Pope Sixtus V. The paintings are by the Milanese artist Giovanni Battista Pozzo (1563-1591). The altar painting by Cesare Nebbia depicts the martyrdom of St. Lawrence. In this chapel are venerated Saint Genesius of Rome, patron of actors, in the act of receiving baptism, and the bishop Pope Saint Eleuterus.
The valuable ceiling of the nave and of the presbytery is made in polychromed gilt wood, carved to the design of Carlo Maderno.
References:Sigmaringen Castle was first mentioned in the year 1077 in the chronicles of Petershausen monastery. The oldest parts of the castle are concealed beneath the alterations made during the 17th and the 19th centuries. The secret of the earliest settlement built on this defendable rock will never be fully revealed: large-scale excavation work would be necessary, which the extensive land development renders impossible. Judging from the many Roman remains unearthed in the area around Sigmaringen, the 12th century keep known as the 'Roman Tower' could be traced back to a Roman predecessor.
The castle remains that have been preserved (gate, great hall and keep) date back to the Staufer period around 1200. The castle remains were integrated into subsequent buildings. The foundations of the castle buildings are to a large extent identical to the surrounding castle wall.
These remains give us a good idea of how the castle might have looked during the 12th century.